The cable television industry has migrated to a digital television signal over the past several years. The digital television signal has myriad advantages over the traditional analog signal. These advantages typically include, among others, higher picture quality, more available channels, an addressed network, etc.
Another such advantage of the digital television signal is that the consumer can communicate with the headend service provider and add or remove a requested program/channel to or from the customer's subscription. In some systems, this is achieved from the headend control system by sending an entitlement management message (EMM) to the conditional access device at the customer's location. The conditional access device may be a point of deployment (POD) module, which is a personal computer card (PC Card, alternately PCMCIA) form factor that plugs into newer television models or set-top boxes. The EMM alerts the conditional access device that at least one channel has been added or removed from the customer's subscription, and the conditional access device adds or removes the channel(s) in response to the EMM. The EMM is typically encrypted to ensure that a user cannot change his/her subscriptions at the conditional access device. Because the EMM can come at any time, a receiver at the host must be powered and ready to receive the message.
However, current EnergyStar™ certification requirements for televisions necessitate that televisions in standby mode must use no more than 15 Watts of power. Moreover, 2.5 Watts of this power is allocated specifically for the conditional access device under the Host-POD Interface specification, specifically referenced in the standard for American National Standards Institute Society of Cable and Telecommunications Engineers (ANSI/SCTE) 28 2003. Consumer electronic manufacturers currently have a difficult time meeting this requirement. Thus, there exists a heretofore unaddressed need in the industry.